Apparatus for generation and use of lift gas

ABSTRACT

A balloon launch unit produces lift gas to enable balloon launch or to allow the prolongation of balloon flight. A method of using the balloon launch unit includes reforming a fuel source by reaction with water to generate hydrogen-rich lift gas mixtures, and injecting the lift gas into a balloon. The reforming operation includes causing the combustion of a combustible material with ambient oxygen for the release of energy; and heating a reforming combination of reaction fuel and water with the energy released from the combustion of the combustible material, to a temperature above that required for the reforming reaction wherein the fuel and water sources are reformed into lift gas. The amount of the combustible material combusted is sufficient to result in the release of enough energy to heat an amount of the reforming reaction fuel and water sources to the temperature above that required for the reforming reaction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.11/392,898 titled “Apparatus And Method For Extracting Petroleum FromUnderground Sites Using Reformed Gases,” filed Mar. 29, 2006, which ishereby incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to production and use of lift gas and moreparticularly to production of lift gas for enabling high-altitudeballoon launches and balloon flights.

BACKGROUND OF THE INVENTION

High-altitude scientific balloon flights provide useful information onterrestrial and planetary research including research and monitoring ofweather, and in particular, research and monitoring of weather fromremote locations.

Conventional technology for filling and launching high-altitude balloonsdepends on having a sufficient quantity of hydrogen, helium or otherlike lift gas on site or on-board the balloon. Helium gas is difficultto transport due to the need to constrain gases within heavy,high-pressure cylinders. These heavy cylinders make poor candidates foruse in remote locations or on-board balloon flights. Hydrogen gas istypically stored in a similar manner as helium gas and additionally isproduced by non-portable electrolytic hydrogen generator systems thatrequire large amounts of electrical power. As was the case with heliumgas, hydrogen gas is a poor candidate for use in remote locations oron-board balloon flights.

Accordingly, as recognized by the present inventors, what is needed is amethod and apparatus for portably producing lift gas that allows forboth the relatively inexpensive production of lift gas and the capacityto produce lift gas at remote sites. In addition, there is a need in theart for producing lift gas on-board balloon flights to extend durationof flight time.

It is against this background that various embodiments of the presentinvention were developed.

BRIEF SUMMARY OF THE INVENTION

In light of the above and according to one broad aspect of oneembodiment of the present invention, disclosed herein is a method forgenerating and using lift gas, e.g., hydrogen-rich gas mixtures, forfacilitating the buoyancy of a balloon, and in particular ahigh-altitude balloon. Preferred embodiments of the present inventioninclude generating and using hydrogen-rich gas mixtures for launchingballoons and in particular launching balloons from remote locations,and/or for extending the duration of balloon flights and in particularextending the duration of high-altitude balloon flights.

In one example, the methods of the invention include reforming orreacting a fuel or other hydrocarbon source with water to generatehydrogen-carbon dioxide rich “lift gas” mixtures and using the lift gasfor buoyancy in a balloon. The fuel or hydrocarbon sources used forgeneration of lift gas include, but are not limited to, alcohols,olefins, paraffins, ethers, aromatic hydrocarbons, and the like. Inaddition, the fuel sources can be from refined commercial products suchas propane, diesel fuels, gasolines or unrefined commercial productssuch as crude oil or natural gas. The water can be introduced into thereforming reactor as liquid water, as steam, or, if the fuel is analcohol or other substance miscible in water, as a component premixedwith the fuel.

The reforming reaction can be driven by the release of energy fromcombustion or a non-combustion source such as electricity. In preferredembodiments the energy is provided by a combustion reaction using acombustible material, and atmospheric air.

In preferred embodiments the lift gas is a hydrogen-carbon dioxide richgas mixture.

The method may also include the addition of a catalyst to the reformingreaction. The catalyst reduces the temperature required to reform thefuel source and improves selectivity of hydrogen and carbon dioxideproduction.

According to another broad aspect of another embodiment of the presentinvention, disclosed herein is an apparatus or device for producing liftgas useful in providing lift or buoyancy to a balloon. In one example,the apparatus may include a first storage container for storing acombustible material used in the combustion reaction; a second storagecontainer for storing a fuel or alternative hydrocarbon source used inthe reforming reaction; a third storage container for water to bereacted with fuel in the reformer; a first chamber having an inlet andan outlet, the first chamber for combusting the combustible materialwith ambient air for the release of energy, the inlet of the firstchamber fluidly coupled with the first storage container; and a secondchamber having an inlet and an outlet, the inlet of the second chamberfluidly coupled with the second and third storage containers, a portionof the second chamber positioned within a portion of the first chamber,the second chamber fluidly isolated from the first chamber. In oneexample, the energy released in the first chamber heats the fuel andwater sources used in the reforming reaction in the second chamber to atemperature above that necessary for the reforming reaction therebyreforming the fuel and water sources into lift gas exiting the outlet ofthe second chamber and into a balloon or other container for capturingthe lift gas.

In one example, the first chamber includes an igniter for igniting thecombustible material, and the second storage container may include amixture of water with the reforming reaction fuel source. The secondchamber may be adapted to receive a catalyst to reduce the temperatureand amount of energy required to heat the reforming reaction fuel andwater sources to a temperature above that necessary for the reformingreaction to proceed.

In another embodiment, the apparatus may include a first heat exchangercoupled with the outlet of the first chamber and thermodynamicallycoupled with the second chamber, the first heat exchanger forpre-heating the reforming reaction fuel and/or water sources. Theapparatus may also include a second heat exchanger coupled with theoutlet of the second chamber and thermodynamically coupled with theinlet of the second chamber, the second heat exchanger for pre-heatingthe reforming reaction fuel and or water sources and for cooling thegenerated lift gas.

According to another broad aspect of another embodiment of the presentinvention, disclosed herein is an autothermal apparatus for generatinglift gas for providing buoyancy to a balloon and in particular to ahigh-altitude balloon. In one example, the apparatus may include asingle reaction chamber for combining a reforming fuel source, water,and an oxidizer; a reforming reaction fuel delivery pipe for delivery ofthe reforming fuel source; another pipeline for water; an oxidizingagent delivery pipe for delivery of oxygen or other like oxidizingagent; and a lift gas outlet port for removal of lift gas produced inthe reaction chamber. In one example, a counter-flow heat exchangerprovides energy/heat from the released lift gas to the incoming reformerfuel to facilitate the autothermal reformer reaction in the reactionchamber.

In one example of the autothermal reformer apparatus, a reaction chamberheater pre-heats the reaction chamber to initiate the reforming reactionand subsequent formation of lift gas. In another example, the reactionchamber includes a catalyst bed to facilitate autothermal reforming ofappropriate reforming fuel sources.

According to another broad aspect of another embodiment of the presentinvention, disclosed herein is a portable balloon launch unit forgenerating the required lift gas to launch a balloon, and preferably ahigh-altitude balloon. Balloon launch units of the present inventioninclude the reformer apparatus of the invention, the reformer apparatusbeing portable. Typical balloon launch units of the invention have sizedimensions of approximately 1 m³ and weight less than 60 kg. In someembodiments the size dimensions are approximately 0.5 m³ and weigh aslittle as 20 kg. Other dimensions can be used in this regard (largersize dimensions or heavier equipment), but size and weight are minimizedwhere the balloon launch is required at a remote location.

The features, utilities and advantages of the various embodiments of theinvention will be apparent from the following more particulardescription of embodiments of the invention as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of an embodiment of the present inventionfor producing lift gas useful in launching a high-altitude balloon.

FIG. 2 illustrates an example of an embodiment of the present inventionfor producing lift gas useful on-board a high-altitude balloon to extendthe flight time and/or expense of the balloon flight.

FIG. 3 illustrates an example of an apparatus for producing lift gas, inaccordance with one embodiment of the present invention.

FIG. 4 illustrates another example of an apparatus for generating liftgas, in accordance with one embodiment of the present invention.

FIG. 5 illustrates an example of a system of an on-board reformerapparatus in accordance with the present invention.

FIG. 6 illustrates an example of a system useful in day operation of anon-board water ballast generator in accordance with the presentinvention.

FIG. 7 illustrates an experiment demonstrating low-pressure hydrogencombustion in accordance with embodiments of the present invention.

FIG. 8 illustrates a system for separating higher molecular weightcomponents from lower molecular weight components of lift gas asgenerated by embodiments of the present invention.

FIG. 9 is a plot of average molecular weight against hydrogen recoveryachieved experimentally using membrane separation of lift gas inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention provide for the creation of liftgas which is used for providing buoyancy to balloons, and in preferredembodiments providing buoyancy to high-altitude balloons. In someembodiments the buoyancy provided by the lift gas is used to launchballoons and preferably to launch balloons from remote locations. Inthese embodiments the lift gas can by generated by an apparatus locatedeither on- or off-board the balloon. In other embodiments, the buoyancyprovided by the lift gas is generated on-board the balloon and is usedto extend the duration of the balloon's flight.

For purposes of the present invention lift gas is typically any gasformed during the reforming reactions of the present invention (seebelow) and is preferably a hydrogen-rich gas or hydrogen and carbondioxide containing gas. Various embodiments of the present invention aredisclosed herein. Note that the majority of the disclosure is directedtoward creating a lift gas that is ultimately used for buoyancy in aballoon, however, methods and apparatus of the invention can also beused to create lift gases useful in providing lift to any object in needthereof.

For purposes of the present invention the term “buoyancy” refers to theupward pressure exerted upon an object by lift gas to provide lift tothe object. In addition, the term “balloon” refers to any objectdesigned to be inflated with gas that is lighter than the surroundingair causing the “balloon” to rise and float in the atmosphere. Balloonscan include high-altitude balloons, weather balloons, blimps, airships,etc. Note that balloons typically include a flexible constrainingmaterial for capture of the lift gas. Further, the term “remotelocation” refers to geographic locations where traditional travelmethods (airplane, ground transportation, etc) are either extremelydifficult to accomplish or are extremely costly, for example, Arctic,Antarctic, various underdeveloped countries, mountain tops, deserts,other planets, etc. A remote location can also be a location on anoffshore drilling platform, the deck of a ship, and other like man-madelocations that would provide a difficult spot to move heavy and/orexpensive equipment.

Embodiments of the present invention provide reformer apparatus forgenerating lift gas used in balloon launches or flight and in preferredembodiments lift gas used to launch balloons from remote locationsand/or to extend the duration of high-altitude balloon flights.Apparatus embodiments of the invention are portable, self-contained andenergy efficient, able to generate lift gas through reforming of a fuelsource. Each apparatus utilizes a reforming reaction to generate thelift gas and a combustion reaction to provide the energy required toreform a fuel and generate the lift gas. Various apparatus embodimentsare provided herein based on either separating the reforming reactionfrom the combustion reaction or based on combining the reformingreaction with the combustion reaction (referred to herein as autothermalreforming). In addition, the apparatus typically includes heat exchangeelements to facilitate heat transfer from the high temperature lift gasto incoming reformer and/or combustion fuel. The transfer of heatfacilitating the reforming reaction and lowering the energy required tocomplete the lift gas formation. Note that various apparatusconfigurations are envisioned to be within the scope of the presentinvention as long as the apparatus provides for on-site, portable,energy efficient reforming reactions (and preferably steam reformingreactions) that produce lift gas useful in the buoyancy of a balloon orother like object.

Balloon Launch

In FIG. 1, a launch unit 100 having a high-altitude balloon 101 isillustrated, the unit includes a portable, self-contained reformer 102in accordance with the present invention. The self-contained reformer102 generates lift gas for buoyancy in a balloon 101 or other likeobject, e.g., aerostats, dirigibles, etc. Referring to FIG. 1, a balloon101 or other like object is located on a launch site 104 having aportable reformer 102 of the invention. The reformer generates lift gasthat enters the balloon. Various techniques can be used to constrain theballoon on the ground (see arrow 106) until the balloon is ready forlaunch. Note also that other devices can accompany the reformer at theballoon launch site, for example, a membrane for separating highermolecular weight gas components from lower molecular weight componentsof the lift gas (see below).

Balloon launch units 100 of the present invention are portable, havingthe capacity for transport on a standard vehicle, helicopter orairplane. For example, balloon launch units of the present inventiontypically include a self contained reformer with a size between 0.5 and2 m³ and weigh less than 60 kg.

In one embodiment, to perform a launch, the unit, together with itsreformer apparatus, combustion fuel, water, and the balloon or otherlike object and its payload are brought to the launch site by truck,boat, helicopter, conventional balloon or other conveyance. In oneembodiment, the reformer apparatus is then turned on, causing a fan (orother like device) to deliver air into the combustion chamber. Fuel isthen fed into the combustion chamber and the air fuel mixture isignited, heating the reformer reactor. Once the reformer reactor isbrought to adequate temperature, fuel and water are fed into theapparatus, (see below) where they will react with each other in thepresence of a catalyst to produce a hydrogen-rich lift gas mixture,which will also contain some carbon dioxide and possibly some carbonmonoxide or methane as well. This gas mixture will be lighter than air,and can be fed into the balloon for direct use as lift gas.Alternatively, the unit's output can be sent through a gas separationmembrane, pressure-swing adsorption system, or other device, to removemuch of the non-hydrogen components, thereby reducing the lift gas'smolecular weight further before being fed to the balloon. In eithercase, once a sufficient amount of gas has been generated to produce thedesired amount of balloon buoyancy, the reformer apparatus is turnedoff. The balloon is then disconnected from the device, sealed, andlaunched together with its payload.

The advantage of this procedure compared to the current state of the artis that no heavy compressed gas cylinders need to be transported to thelaunch site. Instead, locally available fuel and water can be used toenable balloon launch. This feature would be advantageous for any launchsystem, but becomes especially so it we consider the logistics problemsassociated with transporting compressed gas cylinders to enableconventional balloon launches in remote or rugged areas, islands,underdeveloped countries, military theaters of action, etc.

Description of the reformer apparatus and chemical reactions useful inthe present invention are provided below.

Balloon Flight

FIG. 2 illustrates an example of an embodiment of the present inventionwhere a reformer apparatus 200 embodiment is on-board a balloon gondola202 and useful in extending the duration of the balloon flight orallowing for the balloon flight on other terrestrial bodies.

Balloons 101 typically must vent gas in the daytime when heat from thesun makes the gas within the balloon expand. However, the loss of thegas during the daytime means that as the balloon cools (for exampleduring the evening hours), the balloon no longer has enough gas orbuoyancy to float. At this point the balloon must either drop ballast ortake on more gas to continue flight at the same altitude as during thepreceding day. The cycle must be performed the next day (temperaturecycle (until the consumables required to release ballast/generate liftgas have been exhausted. At this point the flight must end.

Embodiments of the present invention diminish/overcome the abovecyclical nature of balloon flight by providing the capacity to generatelift gas during flight and the capacity of generating ballast duringflight.

Reformer reactor apparatus of the present invention generate lift gaswhen the temperature of the balloon falls to the point where the balloonbegins to loose altitude. This typically occurs at nighttime when heatfrom the sun no longer impacts the balloon surface. The appropriateamount of lift gas can be generated using the reformer apparatus andappropriate fuel source when additional lift gas is required. This liftgas production reduces and/or eliminates the need to drop ballast duringthe evening. Note that the amount of lift gas generated during thenighttime is modified by the consumption of an amount of fuel source onboard the balloon, i.e., weight of a fuel source consumed. In addition,rather than venting gas during the daytime, lift gas from the ballooncan be reacted with air to produce water ballast (note that the CO₂portion of the lift gas will not react with air and so is vented). Theproduction of ballast limits the amount of gas that needs to be ventedduring the day (high temperature), because it makes the balloon heavier,the dropping of the ballast when the temperature decreases (nighttime)then reduces the amount of lift gas that needs to be produced. The netresult of these benefits is a potential tripling of the flight timeduration while using the devices of the present invention (overconventional ballooning technology).

In alternative embodiments, an auxiliary balloon (not shown) is providedalong with a main buoyancy balloon, the auxiliary balloon captures andreleases the lift gas generated using reformer embodiments of thepresent invention (see below). The auxiliary balloon can be used incombination with a main balloon that has the capacity to constrain thelift gas during the daytime (greatest amount of gas expansion) but isunder-inflated during the nighttime. The auxiliary balloon would then beinflated during the nighttime to provide the additional lift requiredwith the cooling of the gas.

Note also that the fuel source, water, combustibles, and other likematerials are stored on the balloon as is well known in the art, forexample, in a storage area on the gondola.

Reformer Apparatus

A first illustrative embodiment is described in FIG. 3 for separatereformer and combustion reactions, followed by an embodiment describedin FIG. 4 for autothermal reforming and production of lift gas from asingle reaction chamber.

FIG. 3 illustrates an example of a self-contained, portable apparatus300 for generating lift gas (shown as arrow 302) for injection into aballoon, in accordance with one embodiment of the present invention.

In FIG. 3, an embodiment of the apparatus may include a first storagecontainer (not shown) storing a combustible material, such as an alcoholor olefin. A second storage container (not shown) is also provided,which may include a reforming reaction fuel source, such as an alcohol,olefin, paraffin, and the like or mixtures thereof. If the reformer fuelis an alcohol or other chemical miscible in water, the water may bemixed with the fuel in this container. If the reformer fuel is ahydrocarbon such as a paraffin not miscible in water, a third container(not shown) is required for the water to be reacted with the fuel in thereformer chamber.

In one example, a first chamber 304 has an inlet port 308 and an outletport 310 and is adapted to provide for the combustion of the combustiblematerial. In one example, the first chamber includes an igniter such asa spark plug 312 or other conventional igniter, and a nozzle 314 coupledwith the inlet port 308 of the first chamber 304. The inlet port 308 ofthe first chamber may be coupled with the first storage container sothat the contents of the first storage container may be introduced intoand combusted within the first chamber. The first chamber also includesa port 316 for introducing combustion air into the first chamber. Thefirst chamber is also adapted to receive a portion of the second chamber306, described below, so that the energy/heat from the combustion of thecombustible material from the first storage container within the firstchamber is transferred into a portion of the second chamber. The outletport 310 of the first chamber, in one example, is near the inlet port ofthe second chamber (not shown), and a heat exchanger is used to allowthe combustion exhaust gas to heat the fuel and water entering thesecond chamber. Alternatively, the outlet of the first chamber can feedto a heat exchanger 318 located inside the second chamber, which therebyallows the combustion exhaust gases produced in the first chamber toprovide the heat to drive the reforming reactions in the second chamber.

The second chamber 306 has an inlet port (shown as arrow 320) and anoutlet port 302. In one example, the inlet port is coupled with thesecond storage container 330 and receives the contents of the second andthird storage containers. The second chamber may also include a port 322for receiving catalyst material within the second chamber.

In one example, the second chamber is positioned within the firstchamber, such that the combustion heat/energy from the first chamberheats the reforming reaction fuel and water sources contained within thesecond chamber to a point where the fuel source vaporizes and reformsinto a lift gas which exists out of the outlet port of the secondchamber. In one example, the first and second chambers are fluidlyisolated.

A catalyst 324 may be utilized within the second chamber in order toreduce the temperature and amount of energy required to heat thereforming reaction fuel and water sources to their reaction temperature,and such catalysts are dependent upon the fuel source but include ironbased catalyst, zinc oxide, copper based catalyst, nickel, ruthenium onalumina, and the like.

In one example, a first heat exchanger 318 is coupled with the outletport of the first chamber (the combustion chamber) and isthermodynamically coupled with a portion of the inlet port of the secondchamber. In this manner, the hot combustion exhaust gases from the firstchamber are used to preheat the reforming reaction fuel and or watersources as they are being introduced into the second chamber forvaporization/reformation into a lift gas.

A second heat exchanger 326 may also be utilized, wherein the secondheat exchanger 326 is thermodynamically coupled with the outlet ports302 and the inlet port 320 of the second chamber, which provides thedual benefit of preheating the reforming reaction fuel and/or watersources prior to entry into the second chamber, as well as cooling thelift gas which is expelled from the outlet ports of the second chamber.Note that various illustrative temperatures are shown to illustrateheat-exchange, but are not meant to limit the range of temperaturesuseful in the present invention.

FIG. 4 illustrates another example of a self-contained portableapparatus 400 for generating lift gas for providing buoyancy to aballoon or other like device, in accordance with another embodiment ofthe present invention. The embodiment illustrated in FIG. 4 provideswhat the inventors term an “autothermal reformer” for the production oflift gas useful in providing buoyancy to a balloon.

An autothermal reformer 400 of the present invention directly reacts areformer fuel source with oxygen or other like oxidizers in a singlechamber 402. Embodiments of the reformer provide an environment forreforming a fuel source with a feed at proper temperature and pressureresulting in the release of lift gas. Since the reforming reaction isfavored by low pressure, in preferred embodiments pressure in theautothermal reactor should be kept under 50 bar. Embodiments of theautothermal reformer may combine counter-flow heat exchange elements toenhance heat transfer and energy efficiency of the autothermal reformer.

FIG. 4 shows one embodiment of the autothermal reformer apparatus 400 ofthe invention. Note that other autothermal reformer apparatus areenvisioned to be within the scope of the present invention as long asthey provide at least a reaction chamber with a reforming reaction fuelsource inlet, an air or oxidizing agent inlet and a lift gas outlet.

Referring to FIG. 4, an autothermal reformer apparatus 400 is shownhaving a reaction chamber 402, a reforming reaction fuel delivery pipe(fuel pipe) 404 for delivery of a reforming reaction fuel, a lift gasoutlet port (outlet port) 406 for release of produced lift gas, and anoxygen or other like gas inlet pipe (gas pipe) 408 for delivery of a gasused in the combustion of the reforming reaction fuel in the reactionchamber.

Still referring to FIG. 4, the reaction chamber 402 is of sufficientsize and shape for autothermal reforming of a fuel source. Differentchamber geometries can be used as long as they constrain the autothermalreforming reactions of the present invention and provide sufficientchamber space to produce an amount of lift gas necessary at a balloonlaunch site or on-board an in-flight balloon. A catalyst bed (see below)410 is typically integrated into the reaction chamber for optimizedautothermal reforming reactions. In the embodiment shown in FIG. 4, thefuel pipe 404 is coupled to the outlet port to form a counter-flow heatexchanger 412 so that the energy/heat from the exiting lift gas istransferred to the reforming fuel entering the reaction chamber via thefuel pipe. In addition, the fuel pipe 404 typically enters at a first(or, in this case, top) end 414 of the reaction chamber and releases thefuel toward the second (or, in this case, bottom) end 416 of thereaction chamber. This configuration enhances heat release from theheated reformer fuel into the contents of the reaction chamber. Releaseof fuel into the chamber 402 can be via a nozzle 415 or other likedevice. The gas pipe 408 is typically coupled to or adjacent to the fuelpipe and releases the oxygen or other like gas adjacent to the releaseof the reformer fuel 417. Note that other configurations of reformerfuel and water delivery, oxygen or other oxidizing agent delivery andlift gas release are envisioned to be within the scope of the inventionand are shown in FIG. 4 as an illustration of one embodiment.

In use, the reaction chamber of the autothermal reformer apparatus istypically preheated to a temperature sufficient to start the reformingreaction, i.e., between 200° C.-400° C. Preheating can be accomplishedby a reaction chamber integrated heating element, a heating coil, anexternal combustor heating system, or other like device (not shown).

The reformer fuel source (with or without water, see below) is fed intothe reaction chamber via the fuel pipe 404. Note that once lift gas isproduced in the reaction chamber, the reformer fuel is heated prior todelivery into the reaction chamber by the exiting lift gas (shown asarrow 418) via the counter-flow heat exchanger. At approximately thesame time that the reformer fuel is being delivered to the reactionchamber, the oxygen or other oxidizing agent being delivered to thereaction chamber via the inlet pipe. Various reformer chemical reactionsare described below.

Once the reforming reaction has been established within the reactionchamber the reaction chamber heating element may be shut off to conserveenergy. Note also that the amount of water combined into the reformingfuel can be adjusted to control the reforming temperatures.

Chemical Processes

The generation of lift gas(es) will now be described, for examplegenerating hydrogen rich gas, i.e., a mixture of hydrogen gas (H₂),carbon monoxide (CO) and/or carbon dioxide (CO₂). The constituents oflift gas produced by embodiments of the present invention is determinedby the reaction constituents and conditions as described below, butgenerally include at least hydrogen gas.

Embodiments of the present invention provide processes for producinglift gas from the reforming of select fuel sources, such as solid,liquid and/or gaseous hydrocarbons, alcohols, olefins, paraffins,ethers, and other like materials. Illustrative fuel sources for use inthe reforming reaction include, but are not limited to, methanol,ethanol, propane, propylene, toluene and octane.

The combustor fuel can include both refined commercial products such aspropane, diesel fuel, and/or gasoline, or unrefined substances such ascrude oil, natural gas, coal, or wood. In preferred embodiments the liftgas mixture is generated from the steam reforming of fuels such asmethanol or ethanol.

The methods of the invention are reproducible and easily performed inthe portable inventive devices described herein. The processes of theinvention are superior to electrolytic hydrogen generation which requirelarge amounts of electrical power and are typically non-portable. Thepreferred processes of the invention are also superior to the productionof hydrogen by cracking or pyrolyzation of hydrocarbons without the useof water because much more lift gas is produced for a given amount offuel consumed.

The methods of the invention use easily obtained fuel sources such as ahydrocarbon sources, water, and atmospheric air.

Embodiments of the invention also include combustible materials tosupply the energy to drive the reforming reactions of the presentinvention. Combustible reactions can include a source of energy that isburned with ambient air for the release of energy. Note that inalternative embodiments of the invention, the energy required to drivethe reforming reactions of the invention can be provided bynon-combustion sources, such as solar, nuclear, wind, grid electricity,or hydroelectric power.

In some embodiments of the invention, the reforming reaction to generatehydrogen rich gas and combustion reactions to drive that reaction bothincorporate the same fuel. For example, methanol can be used as thereforming fuel source and as the source of combustion to drive thereforming reaction.

In more detail, the invention provides reforming processes of anyreforming fuel source to generate, for example, H₂, CO and/or CO₂. Thelift gas forming reactions of the invention are endothermic, requiringan input of energy to drive the reaction toward fuel reformation.

In one embodiment, the energy required to drive the reforming reactionis provided through the combustion of any combustible material, forexample an alcohol, a refined petroleum product, crude petroleum,natural gas, wood, or coal that provides the necessary heat to drive theendothermic steam reforming reaction.

In another embodiment, the energy required to drive the reformingreaction is provided via any non-combustible source sufficient togenerate enough heat to drive the reforming reaction to substantialcompletion.

The present combination of reforming and combustion reactions can beperformed within a portable reaction vessel, for example the devicesdescribed herein (see FIG. 3 and FIG. 4). This is in contrast toelectrolysis hydrogen gas formation which requires large amounts ofelectrical power and non-portable machinery for the generation of thegas.

The following reactions provide illustrative processes for reforming afuel source to produce a lift gas used in providing buoyancy to aballoon or other like object. Several illustrative combustion reactionsthat provide the energy required to drive those reforming reactions arealso provided. In one embodiment, provided as Reaction 1, a hydrogenrich gas is formed using pure methanol. Note that the reforming reactionand combustion reaction can be performed in separate reaction chambers(see FIG. 3) or can be combined and performed in a single reactionchamber (see FIG. 4). The following 12 reactions illustrate a separationof the reforming and combustion reactions, however, as is shown in FIG.4 and discussed in greater detail below, an autothermal reformingreaction can be accomplished by directly reacting the fuel sources ofthe invention with oxygen in a single reaction chamber. Theseautothermal reactions can be performed in the presence or absence ofwater.

Separate chamber reactions (see FIG. 3):CH₃OH→CO+2H₂  Reaction 1:

Reaction 1 comes with an ΔH of +128.6 kJoules/mole. This means that thissame amount of energy must be contributed by the combustion reaction todrive the reaction toward the formation of CO and H₂.

In an alternative embodiment, the reformed fuel, e.g., methanol, can bemixed with water as shown in reaction 2:CH₃OH+H₂O→CO₂+3H₂  Reaction 2:

Reaction 2 comes with an ΔH of +131.4 kJoules/mole. As above in Reaction1, for a small price in energy, an appropriate fuel source can becracked to form hydrogen gas, carbon monoxide and/or carbon dioxide. Ifwe compare Reaction 2 to Reaction 1, we observe that for essentially thesame energy, the use of water allows the hydrogen yield to be increasedby 50%. This is why it is generally advantageous to employ both waterand fuel in the proposed reforming system.

Reactions 3-8 illustrate several other reforming reaction fuel reactionsthat are in accordance with the present invention.(ethanol):C₂H₅OH+3H₂O→2CO₂+6H₂  Reaction 3(propane):C₃H₈+6H₂O→3CO₂+10H₂  Reaction 4(propylene):C₃H₆+6H₂O→3CO₂+9H₂  Reaction 5(tolunen):C₇H₈+14H₂O→7CO₂+18H₂  Reaction 6(octane):C₈H₁₈+16H₂O→8CO₂+25H₂  Reaction 7(methane):CH₄+2H₂O→CO₂+4H₂  Reaction 8

Note that in general Reactions 1-8 (as well as other reforming reactionsof the invention) result in large increases in the number of moleculesof products compared to reactants, so all are benefited by beingperformed under low pressure.

In alternative embodiments the reforming reaction is performed in thepresence of a catalyst, for example, when the reforming reaction fuel isan alcohol, e.g., methanol or ethanol, which is combined with water, thefeed is passed over a copper on alumina, copper on zinc oxide, or othercopper-based catalyst at temperatures above 250° C. (although betterresults may be obtained at higher temperatures). Thus, for example, thereactor chamber in FIG. 4 could be prepared with a copper on zinc oxidecatalyst when the reformer fuel is an alcohol.

When the reforming reaction fuel is a hydrocarbon, e.g., paraffins,olefins, aromatics, combined with water, the feed is passed over an ironbased catalyst at temperatures above 300° C. (although better resultsmay be obtained at higher temperatures).

When the reforming reaction fuel is methane combined with water, thefeed is passed over a nickel or ruthenium based catalyst at temperaturesabove 500° C. (although better results may be obtained at highertemperatures).

These are examples; other catalyst types may also be effective forenhancing the described reforming reactions.

In some embodiments, combinations of olefins, paraffins, and aromatics(as found in crude petroleum) can be used as the reforming reaction fuelsource. In other embodiments, a crude petroleum product is used as thereforming reaction fuel source where the crude petroleum product isfirst treated to remove sulfur or other impurities (sulfur can poisoncatalyst involved with the reforming reaction). Note that otherreforming reaction fuel sources may also need to be pre-treated forremoval or sulfur or other impurities, for example, natural gas.

In another embodiment of the invention, a reforming reaction fuel sourcecan be generated from a pre-source. In one example, gamma alumina isused to react dimethyl ether with water to make methanol via Reaction 9:(CH₃)₂O+H₂O→2CH₃OH  Reaction 9:

The methanol produced in Reaction 9 can then be reacted with more watervia Reaction 2 to produce the lift gas. As such, using a mixed gammaalumina and copper catalyst bed, dimethyl ether and water are reacted toobtain the net result shown in Reaction 10:(CH₃)₂O+3H₂O→2CO₂+6H₂  Reaction 10:

The energy required to drive the reforming reactions is provided byeither combustible or non-combustible sources. In preferred reactionsthe energy is provided by combustion of a combustible material and insome embodiments the combustible material is the same as the reformingreaction fuel source.

An illustrative combustion reaction is shown in Reaction 11. Thecombustion of a source of fuel supplies the energy to drive reactions1-10. An illustrative example is the combustion of methanol with ambientoxygen to release ΔH of −725.7 kJoules/mole. Reaction 11 is shown below:CH₃OH_((e))+ 3/2O₂→CO₂+2H₂O  Reaction 11:

Thus, theoretically (not being bound by any particular theory) forpurposes of this illustration, only ⅕ of the mass of methanol isrequired to be burned to reform methanol via reactions 1 and/or 2. Thisis a small price to pay given that most fuels used in the reformingreaction are cheap, easy to store as a liquid and readily available,even in remote areas of the world.

In general, the required energy to drive the reforming reactions of thepresent invention can be furnished by burning small fractions of thereforming reaction fuel source or by using an alternative fuel or otherheating methods such as nuclear, solar or electric grid power. In eachcase, a much larger number of product molecules is produced than isburned or reacted, allowing a large quantity of lift gas to be producedat low cost.

In yet another embodiment, carbon monoxide derived from variousreforming reactions is separated away from the hydrogen gas using a“membrane” or other separation device and further burned to provideadditional energy to drive the methanol reforming, see Reaction 12.CO+½O₂→CO₂  Reaction 12:

The burning of CO results in the ΔH of −283.0 kJoules/mole, againreleasing heat for use in driving the reforming reactions illustrated inReactions 1-10. It should be noted that by removing the CO, themolecular weight of the lift gas can be reduced from about 11 to aslittle as 2 (i.e. the lift gas can be made into pure, or nearly pure,hydrogen), which may be very advantageous for balloon applications.

With regard to autothermal reforming, a reforming fuel is directlyreacted with oxygen in the presence or absence of water. In alternativeembodiments to facilitate combustion of all of the reforming fuel,oxygen gas, air, or alternative oxidizer materials, e.g., hydrogenperoxide, nitrous oxide, is metered in an amount to react with all ofthe carbon contained in the reforming fuel. The thermodynamics of theautothermal chemical reactions and the presence of a proper catalystwith proper selection of operating temperature and pressure result information of substantially only carbon dioxide and hydrogen gas.However, in use, small amounts of water and other compounds may form bycombustion of hydrogen or other byproduct reactions. Where air is usedas the oxidizer, there will also be nitrogen left over which can serveas part of the lift gas, or be removed through the use of a membrane.

A membrane separator, pressure-swing adsorption, or other methods mayalso be used in lift gas generators using reactions such as reactions(2)-(9) and thus produce a mixture of CO₂ and hydrogen. In these cases,removal of the CO₂ from the lift gas mixture can reduce its molecularweight from 12.5 to as little as 2.

These uses compare with the use of helium or other stored compressedgases as lift gas at a balloon launch site. However, such gases arenormally transported at very high pressures (2200 psi) and in very heavygas bottles (e.g. K-bottles, ˜55 kg each with, for example, 1.1 kg ofHe). Using easily transported methanol to perform Reaction(1) or (2), orother available reformer fuels, allows the on-site production of ahigh-hydrogen-concentration gas without a large electrical requirementneeded for electrolytic gas generators. In this sense, gas generationfor use in the field provides a significant cost benefit overconventional methods for transporting generating a lighter than air gas.

Process embodiments of the invention can take place as a reformingreaction between 200 and 400° C., dependent on the fuel source andcatalyst, and more preferably at about 400° C. As such, the reformingfeed, i.e., fuel and water sources, are heated to boiling temperature,vaporized, then continued to be heated to the above temperature range,where they react to form lift gas. After the reforming reaction, the gasproduct can be cooled. The heat is provided by combustion of a fuel orvia a non-combustible source.

With regard to a combustible reaction to supply the energy to drive thereforming reaction, a spark plug, incandescent wire, or any other commonignition device is typically used to initially start the reaction.

The following description is provided as an illustrative example and isnot meant to limit the description herein.

Step 1: Preheat Reformer Feed, Cooling of Gas

The reformer feed (fuel and water) enters the system at 20° C. Use ofmethanol will be provided for illustrative purposes. The average boilingtemperature for the CH₃OH and H₂O mixture is ˜90° C. Assuming as anexample a small system with a lift gas production rate of 100 standardliters per minute, the heat required to preheat the reformer feed from20 to 90° C. is 202 J/s. The heat lost during this step is 4 J/s. Theaim of this heat exchanger is to have the gas exit at about 35° C.Knowing the preheat will require a total of 206 J/s, the inlettemperature of the hydrogen rich gas needed is calculated to be 130° C.A heat exchanger model shows that a total length of 2.6 m oftube-in-tube exchanger is needed. Coiled, the resulting height is about9 cm.

Step 2: Begin Boiling Reformer Feed, Begin Cooling Gas

The hydrogen rich gas will be leaving the reaction chamber at about 400°C. As it cools to 130° C., a heat of 613 J/s is produced, 16.5 J/s ofwhich is lost. To vaporize the CH₃OH and H₂O, 1308 J/s is needed.Therefore, the gas partially boils the reformer feed. The total lengthof the tube-in-tube required for this process is 2.1 m. When coiled, theresulting height is about 7 cm. The heat exchangers for steps 1 and 2are combined into a single unit.

Step 3: Finish Boiling Reformer Feed, Cool the Combustion Gas

After Step 2, the reforming feed still needs 710 J/s to finishvaporizing, and in this step, 42 J/s is lost. As calculated in Step 5,the combustion gas will leave the reformer at about 648° C. Giving thereforming feed the heat it needs to boil brings the combustion gastemperature down to 127° C. This takes a length of 2.8 m of thetube-in-tube exchanger, which is about 10 cm high when coiled.

Step 4: Finish Heating Reformer Feed

The reforming feed is already vaporized and will finish heating when itcontacts the top plate of a combustion chamber. Heating the reformingfeed from 90° to 400° C. requires 518 J/s. This amount of heat bringsthe temperature of the combustion gas from 1650° to 1360° C.

Step 5: Reforming Reaction

To reform CH₃OH & H₂O, 1080 J/s of power may be used in this example.This section of the heat exchanger also loses 94 J/s to thesurroundings. Accommodating this, the combustion gas temperature dropsfrom 1360 to 648° C. The design length of this multiple tube section isabout 20 cm.

An equation for determining the heat used or needed for these processesis Q=ΣmC_(p)ΔT. The calculations led to obtaining the ΔH and heat lostacross a given section and the section's length. The heat exchangeformulas and calculation methods used for the reformer system design aregiven in Incropera and DeWitt, 1996.

The following examples are provided by way of illustration and are notintended as limiting.

EXAMPLES Example 1 Remote Balloon Launch

Embodiments of the present invention generate high quality lift gasusing minimal consumables, e.g., methanol, water, air, air blower, etc.Compared to the electrolytic lift gas generator, i.e., waterelectrolysis, embodiments of the present invention are smaller, requireless electrical power, require less fuel, have greater practicalproduction rate, and are more reliable.

The reforming of methanol using device embodiments of the presentinvention to produce 100 standard liters per minute of lift gas requiresless than 4 kilowatts of thermal power. An electrolytic hydrogengenerator of this scale requires roughly 25 kilowatts of electricalpower just for the electrolyzer, plus, in remote locations, a generatorto support this level of electrical power production. The mass of such asystem is estimated to be several thousand pounds. The overall powerrequirements combined with the inefficiencies of converting the fuel(gasoline, diesel, propane, etc) to electrical power via the generatorresult in huge consumable requirements relative to the embodiments ofthe invention described herein.

To reduce instantaneous power requirements and system mass, electrolyticgenerators need to gradually collect, compress, and store hydrogen forlater delivery to a balloon in order to provide a reasonable fill rate.Conversely, embodiments of the present invention can substantiallyinstantaneously generate the required rates and thus eliminate hydrogencompression and storage requirements. In addition, electrolyticgenerators require care to prevent damage to the electrolyzer cells. Inremote locations where such a system might be desirable, the risk ofdamage due to contamination is greater. However, embodiments of thepresent invention are much less susceptible to damage from fieldoperations since there are few moving parts and relatively few sensitivecomponents (see FIGS. 3 and 4).

The following comparison is provided between one embodiment of thepresent invention and a conventional electrolytic generator:

TABLE 1 Reformer Apparatus vs. Electrolytic Generator Parameter PresentInvention Electrolytic Generator Mass, kg <100 >2,000 Size, m² <1 >4Electrical Power, kw <0.5 ~100 (from generator) Fuel, g per Std L liftgas 0.1 1.4 Methanol, g per Std L lift gas 0.35 0 Water, g per Std Llift gas 0.2 0.8 Cost, $ <<10,000 >>50,000

Table 1 shows that embodiments of the present invention have advantagesover electrolytic generators in virtually every category. The comparisonis based on the use of methanol as the present invention fuel source anddiesel fuel as the electrolytic generator fuel source. The fuel andmethanol rates for embodiments of the present invention are based ondirect measurements for reforming of a 1:1 molar methanol:water mixture.The fuel rate for the electrolytic generator is based on 25 kWelectrical power (assuming 85% electrolyzer efficiency) and 100 kWthermal power input to the diesel generator, i.e., 25% generatorefficiency. Electrical power shown for the present invention is for anair blower (60 SLPM pumped from ambient pressure to 10 psig) andcontrols and instruments. Power requirements for the present inventionare such that manual-powered generators or pumps could even be used tosupply the needed air flow and electric power.

This example showed the utility of using embodiments of the presentinvention to generate lift gas in remote locations as compared toconventional electrolytic generators.

Example 2 Extension of Stratospheric Balloon Flight Duration

A mission analysis for a 40,000 m³ zero pressure polyethylene balloonflight at an altitude of 100,000 feet is provided. The balloon isassumed to have a mass of 54.6 kg, scaled off of a Raven 4,000 m³balloon (which has a mass of 5.46 kg). It is also assumed the balloon inthis example has a daytime temperature of about 245 K and a nighttimetemperature of about 215 K. Five options are considered for purposes ofthis Example:

1. Ballaster: This is a helium balloon that compensates for theday/night cycle by dropping ballast.

2. Helium Makeup: This is a helium balloon that compensates for theday/night cycle by providing helium makeup gas from a high-pressurecontainer. The container is assumed to have a mass of six times thehelium it contains.

3. Apparatus of the Present Invention (makeup gas only): Embodimentsassume a helium carrier balloon (40,000 m³) with a 5,600 m³ auxiliaryballoon which is filled with makeup gas using the device embodimentsdescribed herein to compensate for the day/night cycle. The device ofthe present Example uses watered methanol to produce CO₂/3H₂ lift gas(based on the Raven 3,000 m³ balloon, such a 5,600 m³ balloon would havea mass of about 15 kg).

4. Apparatus of the Present Invention (Hydrogen Reactor): Embodimentsassume a helium carrier balloon (40,000 m³) with a 5,600 m³ auxiliaryballoon which is filled with makeup gas using the device embodimentsdescribed herein to compensate for the day/night cycle. However, when itcomes time to vent the auxiliary balloon during the day, the lift gas ifrun through a catalytic reactor to react with hydrogen in the lift gaswith air to produce water, which is retained as ballast. The waterballast is dropped the following night which reduces the amount of liftgas needed to be produced each night, thereby extending flight duration.

5. Apparatus of the Present Invention (Hydrogen Reactor and WaterRecycle): Embodiments assume the same parameters as option 4 above,except that the balloon takes off with neat methanol, instead of wateredmethanol, and the water to react with methanol to make lift gas isprovided by using a fraction (about ⅓) of the water produced by thehydrogen reactor. This increases the amount of lift gas that can beproduced by a given amount of carried methanol by about 50%, therebyextending flight.

For purposes of the present Example, embodiments of the devices areassumed to have a mass of 20 kg. Given its volume and float altitude,the flight system has a total floating mass of 668 kg. If we assume thatthe scientific payload gondola for each option has a mass ofapproximately 100 kg, we can calculate the initial consumable supplyavailable to sustain flight, and the amounts of consumables used eachday. The decline in the onboard consumable supply results in the flightbeing terminated. The following flight times are then obtained for eachoption:

Option 1 (Ballaster)—9 days

Option 2 (Helium Makeup)—6 days

Option 3 (Apparatus of the Present Invention (makeup gas only)—17 days

Option 4 (Apparatus of the Present Invention (Hydrogen Reactor))—25 days

Option 5 (Apparatus of the Present Invention (Hydrogen Reactor and WaterRecycle))—35 days

Power requirement evaluations were also performed using the optionsdescribed above. As shown in FIG. 5, a system based on option 3(assuming operation over approximately 4 hours) illustrates generationof lift gas for a nighttime lift. The analysis assumes a 1:1methanol:water reformer feed and a pure methanol fuel for the combustor.FIG. 5 shows that the system can be operated with no auxiliary powerbeyond the induced direct drive turbine and a small electricalgenerator/battery using power from the embodiment detailed in option 3.

Turbine efficiencies are included in the net power delivery requirementsshown. In the system of FIG. 5, the turbine operating on the lift gasdirectly drives the combustion air pump. A small amount of stored poweris used for the start up combustion air blower. The air blower isoperated for only a few minutes until the lift gas is generated to drivethe lift gas turbine. The combustion exhaust turbine charges thisbattery for the next operation cycle. The liquid feed and reformer feedare delivered via a simple pre-charged gas overpressure system requiringno power input other than the control valves.

FIG. 6 illustrates a schematic for daytime operation of the devicedescribed in option 4 above. This system would operate for as short as afew hours each day. FIG. 6 shows the high sensitivity of powerrequirements to operating pressure (for the air blowers). A key featureof this embodiment is that the liquids can be delivered under pressurewith little or no electrical power to produce considerable power in thegas phase.

As such, this Example shows the utility of the present invention.

Example 3 Water Ballast Production From Lift Gas Combustion

The following Example was performed to illustrate the utility ofproducing lift gas during the day and generating ballast in the form ofwater for release in the evening. In addition, the water collected fromcombustion can also be recycled to the reformer at night, therebyreducing the amount of water required at launch of the balloon.

Thermodynamic evaluation of hydrogen combustion with air over a widerange of temperatures and pressures, including near-vacuum conditions,indicated virtually complete conversion. For example, at only 10millibar and 600 K, the equilibrium hydrogen mole fraction is only4×10⁻⁹ after combustion in air.

Based on thermodynamic results, FIG. 7 shows a diagram of a device 700used in testing the feasibility of burning hydrogen at very low pressureover a catalyst. Hydrogen 702 and air 704 were fed to a reactor 706containing a platinum catalyst (Aldrich 20,601-6; 0.5% wt % Pt on Al₂O₃mm pellets) 708. A hydrogen flow of six to seven SCCM and an air flow of21 SCCM were used to provide a slight excess of oxygen at the operatingpressure of about 40 millibar. A temperature of at least 250° C. wasrequired to initiate the reaction. A Drierite® trap 710 size wasoptimized for the task.

An experiment was conducted for three hours at about 40 millibarabsolute pressure with catalyst temperatures between 250-290° C.Hydrogen was successfully burned to generate water. Water sorption onthe Drierite was 0.61 grams versus the theoretical amount of 0.84 grams(full combustion of hydrogen feed). Therefore, about 73% of the expectedwater yield was recovered in the trap. It is likely the remainderescaped through the low-pressure trap, which was operated at ambienttemperature, since no hydrogen was detected at the vacuum pump outlet.Note that lift gas combustion may be accomplished using other tailoredcatalyst types.

This Example shows the feasibility of reducing lift gas volume requiredfor balloon flight while generating ballast for daytime altitudecontrol. The power requirements for pumping the lift gas and combustionair are highly sensitive to pressure. Consequently, the ability toconduct this operation at very low pressure is highly beneficial.

Example 4 Lift Gas Calculations

Reaction 1 (above) results in the production of a gas with an averagemolecular weight of 10.7, producing lift in air, which has an averagemolecular weight of 29. Thus, a balloon with a volume of 1 m³ filledwith CO/H₂ lift gas would generate a buoyancy of about 811 grams.Reaction 2 (above) produces a lift gas with an average molecular weightof 12.5, resulting in a buoyancy of about 729 grams in a 1 m³ balloon.These values compare with the use of helium as a lift gas, which wouldproduce a buoyancy of 1116 grams for the same volume balloon. Note thathelium is transported at very high pressure (2200 psi) and in very heavygas bottles/cylinders (e.g., K-bottles, ˜55 kg each with 1.1 kg He).Using methanol to perform Reaction (1) or (2) on-site would allowballoon launches on Earth without the use of heavy gas bottles or rareand expensive helium.

As such, embodiments of the present invention produce ahigh-hydrogen-concentration lift gas without the large electricalrequirement needed for electrolytic lift gas generators. Using a simplemembrane separation to further enrich the hydrogen concentration of thelift gas, performance comparable to helium gas is obtained.

Example 5 Membrane Product Gas Separation

The following Example illustrates improvement of lift gas quality thatcan be obtained by separating higher molecular weight components fromhydrogen in accordance with the present invention.

When carbon monoxide is present, the separated gas can also be used as afuel. Therefore, the overall efficiency of the reformer apparatusembodiments herein can be improved by reducing the volume of lift gasrequired and by reducing the fuel required to support the reformeroperation.

A number of gas separation methods, such as polymer membranes,high-temperature metallic membranes, or sorption methods (includingpressure-swing or vacuum swing) can be used in the context of theinvention. A Permea Prism® PPA-22 membrane was chosen for use in thepresent Example due to its availability, cost and compact nature.

FIG. 8 shows a schematic of a system 800 used for the membraneseparation of gas components useful in balloon flight. Methanol was fedinto a reformer apparatus 802 of the present invention, which vaporizedand reformed the methanol to hydrogen, carbon monoxide, carbon dioxideand small amounts of dimethyl ether. The product gas was passed througha cold trap 804 to remove any unreacted methanol feed or condensablereaction products. The product gas was then passed through an activatedcarbon trap 806 to remove undesirable organic products that could foulthe membrane. A filter 808 was installed to remove fine particles at theinlet of the membrane 810. The “cleaned” lift gas was then fed to themembrane 810, where the gas was separated into a hydrogen-rich stream812 and a carbon-monoxide-rich stream (retentate) 814. A backpressureregulator 816 installed on the retentate was used to control the flowsplit between the two streams. An inlet pressure gage showed thebackpressure for the system. Flow meters 818 and sample ports 820 wereinstalled on the hydrogen-rich streams.

The Permea PPA-22 membrane was about 2 inches in diameter and about 2feet long (with a weight of about 1 kg). Results demonstrated thatapproximately 90% of the hydrogen generated by the reformer is recoveredin a product with an average molecular weight of 6 to 7. FIG. 9 shows aplot of the results that illustrates the relationship between hydrogenrecovery and average molecular weight of the lift gas.

The present Example illustrates the utility of separating out the highermolecular weight gas products from the lift gas. The modified lift gasprovides higher quality lift to a balloon or other like device and canbe used in combination with the reformer apparatus of the presentinvention.

While the methods disclosed herein have been described and shown withreference to particular operations performed in a particular order, itwill be understood that these operations may be combined, sub-divided,or re-ordered to form equivalent methods without departing from theteachings of the present invention. Accordingly, unless specificallyindicated herein, the order and grouping of the operations is not alimitation of the present invention.

While the invention has been particularly shown and described withreference to embodiments thereof, it will be understood by those skilledin the art that various other changes in the form and details may bemade without departing from the spirit and scope of the invention.

1. A system comprising: a balloon or other flexible container forconstraining a lift gas consisting essentially of hydrogen and carbondioxide; and an apparatus that generates the lift gas by reforming afuel source in a reaction with water either on the ground or on-boardthe balloon, the apparatus releasing the lift gas into the flexiblecontainer; wherein the fuel source is selected from the group consistingof alcohols, olefins, paraffins, ethers, aromatic hydrocarbons, propane,diesel fuels, gasoline, unrefined commercial fuels, crude oil, andnatural gas; and wherein the lift gas is captured in the flexiblecontainer for either launch from the ground or during flights so as tofacilitate the extending flight duration of the balloon or otherflexible container.
 2. The system of claim 1 wherein the reforming of afuel source is driven by energy released from a combustion reactionwithin the apparatus, the combustion reaction resulting from combustionof a combustible material with ambient oxygen.
 3. The system of claim 2wherein the fuel source and combustible material are the same.
 4. Thesystem of claim 3 wherein the fuel source and combustible material arean alcohol, ether, olefin, paraffin, or aromatic hydrocarbon.
 5. Aballoon launch unit comprising: an apparatus that generates a lift gasconsisting essentially of hydrogen and carbon dioxide by reforming afuel source in a reaction with water, wherein the fuel source isselected from the group consisting of alcohols, olefins, paraffins,ethers, aromatic hydrocarbons, propane, diesel fuels, gasoline,unrefined commercial fuels, crude oil, and natural gas; and wherein thelift gas is released into a balloon to provide buoyancy to the balloonand allow for the launch of the balloon.
 6. The balloon launch unit ofclaim 5 wherein the balloon launch is located at a remote site.
 7. Theballoon launch unit of claim 5 wherein the balloon launch is portableand can be transported on a vehicle, helicopter, ship or airplane. 8.The system of claim 1, wherein the apparatus generates ballast foraltitude control of the balloon or other flexible container.